1. Field of the Invention
The present invention relates to a printing inspection apparatus and a printing inspection method for inspecting a printing state of cream solder printed on a substrate, and to a method of generating inspection data used in a printing inspection apparatus for inspecting a printing state of cream solder printed on a substrate.
2. Description of the Related Art
When electronic components are packaged, cream solder is applied on the surface of a substrate before the electronic components are mounted on the substrate. A screen printing method is used extensively as a method of applying cream solder, and a printing inspection is performed after the printing step to inspect a printing state of the cream solder. According to this printing inspection, an image of the substrate after the screen printing is picked up by a camera, and an image pick-up result is subjected to image processing in judging whether cream solder is printed exactly on print portions.
Prior to the printing inspection, inspection data, specifying print portions where the cream solder is to be printed on a substrate as the subject to be inspected, is inputted into the printing inspection apparatus. The inspection data specifies shapes and positions of the print portions on the substrate, and data specifying the printing shapes and positions of solder print portions set on the top surfaces of electrodes provided on a circuit forming surface of the substrate to be used to bond electronic components is inputted for individual electrodes.
Incidentally, the electronic components to be mounted on the substrate have diverse characteristics, and an inspection accuracy in the solder printing step described as above varies depending on the electronic components to be mounted after the printing. In other words, for print portions on which expensive electronic components that demand a high reliability and thereby need a satisfactory printing accuracy are to be mounted, an inspection has to be performed by a method that can ensure a printing accuracy in a reliable manner. On the contrary, for print portions on which electronic components that can be readily bonded through soldering and thereby do not place importance on a printing accuracy are to be mounted, an inspection has to be completed as short a time as possible. For this reason, it is preferable for a printing inspection apparatus performing an inspection to enable a flexible inspection mode in response to the characteristics of the electronic components to be mounted on the substrate as the subject to be inspected.
However, the electrodes used to bond the electronic components are normally formed in the order of thousands to tens of thousands per substrate. Hence, for a flexible inspection mode to be chosen as described above, inspection data and a range to be inspected have to be inputted each time a substrate is changed to another substrate of a different kind. In particular, because a ratio of limited production of diversified products has been on the increase recently in the production pattern at the manufacturing location of electronic equipment, such a data processing work has to be performed for substrates of many kinds at a high frequency. This work, however, is so tedious that it becomes a factor that hinders the improvement of productivity. As has been described, the conventional printing inspection apparatus has a difficulty in achieving an optimal inspection mode in which a balance is kept between the improvement of production efficiency and the securing of a printing accuracy.
Also, the electrodes used to bond the electronic components are normally formed in the order of thousands to tens of thousands per substrate. For this reason, when the aforementioned inspection data is generated or the data is inputted into the printing inspection apparatus, enormous work and time are consumed on the data processing. In particular, because a ratio of limited production of diversified products has been on the increase recently in the production pattern at the manufacturing location of electronic equipment, a data processing work, such as generation and input of inspection data, has to be performed for the substrates of many kinds at a high frequency, and in this regard, there has been a need for a measure for making the data processing work more efficient.